The invention relates to the treatment of aromatic plants or herbs, or of plants containing essential oils (hereinafter named plants).
The plants to which the invention relates are, typically, parsley, chives, thyme, etc., or vegetables. Spices and dry products are excluded therefrom.
Three main presentation methods are known for such plants: fresh, deep-frozen or dehydrated. Presentation in the fresh state has the advantage of good organoleptic qualities, but the disadvantage of a limited preservation period which may be inconvenient. Deep-freezing overcomes this inconvenience, but involves implementing a costly cold chain which can present the risk of being interrupted. Dehydrated presentation permits easy preservation for a long time, but the organoleptic qualities of the plants presented in this manner are generally inferior to those obtained in the fresh state. These organoleptic qualities consist mainly of texture, color, flavor or taste. To these there is added functionality, that is to say the possibility of being utilized under the desired conditions.
It is therefore an aim of the invention to present plants such as aromatic plants or herbs, or plants containing essential oils, in such a way that their organoleptic qualities are identical, or come very close to, those of the fresh state and, at the same time, they can be preserved under conditions comparable to those of the dehydrated state, taking into account the advantages which they present.
According to document U.S. Pat. No. 4,514,428, snacks in the form of apple slices are produced by means of a succession of washing, anti-browning, sugar-impregnation and drying steps. Such a process, which is very specific, does not allow aromatic plants or herbs, or plants containing essential oils, to be treated for the object aimed at above.
Document U.S. Pat. No. 4,313,967 relates to a food product which is stable from the microbiological point of view and which contains a fruit such as grape, date, plum, apricot, apple, peach, cherry or lemon. This product has a water activity of between 0.008 and 0.93.
The document FOOD TECHNOLOGY, vol. 31, no. 4, April 1977, pages 58 to 64, relates to food products of medium humidity and discloses the effects of various additives on the water content.
Documents U.S. Pat. No. 3,952,112, U.S. Pat. No. 4,832,969, U.S. Pat. No. 3,694,236, U.S. Pat. No. 4,361,589, GB-A-1,483,805 and U.S. Pat. No. 4,542,033 disclose the use of sorbitol or glycerol as a humectant for grapes; the production of a dried green vegetable packaged in a black, sealed, oxygen-tight bag; the production of a dried food dehydrated by using Xanthomonas; the production of dried celery by using sugar, followed by drying; and the treatment of whole dried fruits.